Recently, interest in hybrid vehicles with improved fuel efficiency has been increasing. Such hybrid vehicles generally have an electric oil pump (hereinafter, referred to as “EOP”) for supplying a working fluid required for actuating a transmission and a clutch which are interposed between an engine and an actuating motor. Further, the hybrid vehicles generally have an oil pump control unit (hereinafter, referred to as “OPU”) for controlling the electric oil pump operation.
The EOP generates hydraulic pressure by rotating a rotor therein using a driving force of a motor and pumping transmission fluid (ATF) to the transmission. However, when the rotor of EOP is abraded, a proper hydraulic pressure is not generated in the transmission such that the performance of the transmission is decreased. In such a case, the pump needs to be replaced.
Generally, according to a prior art, a system where the EOP and a mechanical oil pump (MOP) are coupled has been used. In such a case, the abrasion situation of the electric oil pump rotor can be diagnosed by measuring and noting that the amount of current consumed when the electric oil pump rotor is worn out is lower than the amount of current consumed when the electric oil pump rotor is normal.
However, often the mechanical oil pump is deleted in order to improve fuel efficiency in an automatic transmission of the hybrid vehicles, and a method for supplying oil by optimally controlling a flow rate by means of only the EOP has been adopted. In other words, the mechanical oil pump which is an oil supply module of a general automatic transmission is deleted in the automatic transmission of the hybrid vehicles, the EOP which is actuated when more than 40V of high voltage, is applied in order to supply a sufficient flow rate. As a result, the amount of current consumed by the EOP decreases, and thus there is a problem in that the prior method for diagnosing abrasion of the electric oil pump rotor based on the amount of current becomes inaccurate.
The description provided above described as a related art is just for helping in understanding the background of the present disclosure and should not be construed as being included in the related art known by those skilled in the art.